diff --git a/libcxx/include/__config b/libcxx/include/__config
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -934,13 +934,6 @@
 #define _LIBCPP_LOCALE__L_EXTENSIONS 1
 #endif
 
-#if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
-// Most unix variants have catopen.  These are the specific ones that don't.
-#  if !defined(__BIONIC__) && !defined(_NEWLIB_VERSION)
-#    define _LIBCPP_HAS_CATOPEN 1
-#  endif
-#endif
-
 #ifdef __FreeBSD__
 #define _DECLARE_C99_LDBL_MATH 1
 #endif
@@ -1312,12 +1305,6 @@
 #define _LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED
 #endif
 
-#if !defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
-#  if defined(_LIBCPP_MSVCRT) || defined(_NEWLIB_VERSION)
-#    define _LIBCPP_HAS_NO_OFF_T_FUNCTIONS
-#  endif
-#endif
-
 #if __has_attribute(diagnose_if) && !defined(_LIBCPP_DISABLE_ADDITIONAL_DIAGNOSTICS)
 #  define _LIBCPP_DIAGNOSE_WARNING(...) \
      __attribute__((diagnose_if(__VA_ARGS__, "warning")))
diff --git a/libcxx/include/fstream b/libcxx/include/fstream
--- a/libcxx/include/fstream
+++ b/libcxx/include/fstream
@@ -198,6 +198,9 @@
 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>
 
+#if defined(_LIBCPP_MSVCRT) || defined(_NEWLIB_VERSION)
+#  define _LIBCPP_HAS_NO_OFF_T_FUNCTIONS
+#endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
diff --git a/libcxx/include/locale b/libcxx/include/locale
--- a/libcxx/include/locale
+++ b/libcxx/include/locale
@@ -203,8 +203,13 @@
 #include <cstdlib>
 #include <ctime>
 #include <cstdio>
-#ifdef _LIBCPP_HAS_CATOPEN
-#include <nl_types.h>
+
+#if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
+// Most unix variants have catopen.  These are the specific ones that don't.
+#  if !defined(__BIONIC__) && !defined(_NEWLIB_VERSION)
+#    define _LIBCPP_HAS_CATOPEN 1
+#    include <nl_types.h>
+#  endif
 #endif
 
 #ifdef _LIBCPP_LOCALE__L_EXTENSIONS